index.html

一本完整的描述Unix Shell 编程的工具书的所有范例

><DT
>11-2. <A
HREF="internal.html#EX47"
><B
CLASS="COMMAND"
>printf</B
> in action</A
></DT
><DT
>11-3. <A
HREF="internal.html#EX36"
>Variable assignment, using <B
CLASS="COMMAND"
>read</B
></A
></DT
><DT
>11-4. <A
HREF="internal.html#READNOVAR"
>What happens when <B
CLASS="COMMAND"
>read</B
> has no
	        variable</A
></DT
><DT
>11-5. <A
HREF="internal.html#READR"
>Multi-line input to <B
CLASS="COMMAND"
>read</B
></A
></DT
><DT
>11-6. <A
HREF="internal.html#ARROWDETECT"
>Detecting the arrow keys</A
></DT
><DT
>11-7. <A
HREF="internal.html#READREDIR"
>Using <B
CLASS="COMMAND"
>read</B
> with
	        <A
HREF="io-redirection.html#IOREDIRREF"
>file redirection</A
></A
></DT
><DT
>11-8. <A
HREF="internal.html#READPIPE"
>Problems reading from a pipe</A
></DT
><DT
>11-9. <A
HREF="internal.html#EX37"
>Changing the current working directory</A
></DT
><DT
>11-10. <A
HREF="internal.html#EX46"
>Letting <SPAN
CLASS="QUOTE"
>"let"</SPAN
> do arithmetic.</A
></DT
><DT
>11-11. <A
HREF="internal.html#EX43"
>Showing the effect of <B
CLASS="COMMAND"
>eval</B
></A
></DT
><DT
>11-12. <A
HREF="internal.html#EX44"
>Forcing a log-off</A
></DT
><DT
>11-13. <A
HREF="internal.html#ROT14"
>A version of <SPAN
CLASS="QUOTE"
>"rot13"</SPAN
></A
></DT
><DT
>11-14. <A
HREF="internal.html#EVALEX"
>Using <B
CLASS="COMMAND"
>eval</B
> to force variable
	        substitution in a Perl script</A
></DT
><DT
>11-15. <A
HREF="internal.html#EX34"
>Using <B
CLASS="COMMAND"
>set</B
> with positional
	        parameters</A
></DT
><DT
>11-16. <A
HREF="internal.html#SETPOS"
>Reassigning the positional parameters</A
></DT
><DT
>11-17. <A
HREF="internal.html#UNS"
><SPAN
CLASS="QUOTE"
>"Unsetting"</SPAN
> a variable</A
></DT
><DT
>11-18. <A
HREF="internal.html#COLTOTALER3"
>Using <B
CLASS="COMMAND"
>export</B
> to pass a variable to an
	      embedded <A
HREF="awk.html#AWKREF"
>awk</A
> script</A
></DT
><DT
>11-19. <A
HREF="internal.html#EX33"
>Using <B
CLASS="COMMAND"
>getopts</B
> to read the
	        options/arguments passed to a script</A
></DT
><DT
>11-20. <A
HREF="internal.html#EX38"
><SPAN
CLASS="QUOTE"
>"Including"</SPAN
> a data file</A
></DT
><DT
>11-21. <A
HREF="internal.html#SELFSOURCE"
>A (useless) script that sources itself</A
></DT
><DT
>11-22. <A
HREF="internal.html#EX54"
>Effects of <B
CLASS="COMMAND"
>exec</B
></A
></DT
><DT
>11-23. <A
HREF="internal.html#SELFEXEC"
>A script that <B
CLASS="COMMAND"
>exec's</B
> itself</A
></DT
><DT
>11-24. <A
HREF="internal.html#EX39"
>Waiting for a process to finish before proceeding</A
></DT
><DT
>11-25. <A
HREF="internal.html#SELFDESTRUCT"
>A script that kills itself</A
></DT
><DT
>12-1. <A
HREF="external.html#EX40"
>Using <B
CLASS="COMMAND"
>ls</B
> to create a table of contents
		for burning a <SPAN
CLASS="ABBREV"
>CDR</SPAN
> disk</A
></DT
><DT
>12-2. <A
HREF="external.html#HELLOL"
>Hello or Good-bye</A
></DT
><DT
>12-3. <A
HREF="moreadv.html#EX57"
><B
CLASS="COMMAND"
>Badname</B
>, eliminate file names
		in current directory containing bad characters and <A
HREF="special-chars.html#WHITESPACEREF"
>whitespace</A
>.</A
></DT
><DT
>12-4. <A
HREF="moreadv.html#IDELETE"
>Deleting a file by its <I
CLASS="EMPHASIS"
>inode</I
>
	        number</A
></DT
><DT
>12-5. <A
HREF="moreadv.html#EX41"
>Logfile: Using <B
CLASS="COMMAND"
>xargs</B
> to monitor system log</A
></DT
><DT
>12-6. <A
HREF="moreadv.html#EX42"
>Copying files in current directory to another</A
></DT
><DT
>12-7. <A
HREF="moreadv.html#KILLBYNAME"
>Killing processes by name</A
></DT
><DT
>12-8. <A
HREF="moreadv.html#WF2"
><B
CLASS="COMMAND"
>Word frequency analysis</B
>
		using <B
CLASS="COMMAND"
>xargs</B
></A
></DT
><DT
>12-9. <A
HREF="moreadv.html#EX45"
>Using <B
CLASS="COMMAND"
>expr</B
></A
></DT
><DT
>12-10. <A
HREF="timedate.html#EX51"
>Using <B
CLASS="COMMAND"
>date</B
></A
></DT
><DT
>12-11. <A
HREF="textproc.html#WF"
>Word Frequency Analysis</A
></DT
><DT
>12-12. <A
HREF="textproc.html#SCRIPTDETECTOR"
>Which files are scripts?</A
></DT
><DT
>12-13. <A
HREF="textproc.html#RND"
>Generating 10-digit random numbers</A
></DT
><DT
>12-14. <A
HREF="textproc.html#EX12"
>Using <B
CLASS="COMMAND"
>tail</B
> to monitor the system log</A
></DT
><DT
>12-15. <A
HREF="textproc.html#GRP"
>Emulating <SPAN
CLASS="QUOTE"
>"grep"</SPAN
> in a script</A
></DT
><DT
>12-16. <A
HREF="textproc.html#DICTLOOKUP"
>Looking up definitions in Webster's 1913 Dictionary</A
></DT
><DT
>12-17. <A
HREF="textproc.html#LOOKUP"
>Checking words in a list for validity</A
></DT
><DT
>12-18. <A
HREF="textproc.html#EX49"
><B
CLASS="COMMAND"
>toupper</B
>: Transforms a file to all uppercase.</A
></DT
><DT
>12-19. <A
HREF="textproc.html#LOWERCASE"
><B
CLASS="COMMAND"
>lowercase</B
>: Changes all filenames in working directory to lowercase.</A
></DT
><DT
>12-20. <A
HREF="textproc.html#DU"
><B
CLASS="COMMAND"
>Du</B
>: DOS to UNIX text file conversion.</A
></DT
><DT
>12-21. <A
HREF="textproc.html#ROT13"
><B
CLASS="COMMAND"
>rot13</B
>: rot13, ultra-weak encryption.</A
></DT
><DT
>12-22. <A
HREF="textproc.html#CRYPTOQUOTE"
>Generating <SPAN
CLASS="QUOTE"
>"Crypto-Quote"</SPAN
> Puzzles</A
></DT
><DT
>12-23. <A
HREF="textproc.html#EX50"
>Formatted file listing.</A
></DT
><DT
>12-24. <A
HREF="textproc.html#COL"
>Using <B
CLASS="COMMAND"
>column</B
> to format a directory
	        listing</A
></DT
><DT
>12-25. <A
HREF="textproc.html#LNUM"
><B
CLASS="COMMAND"
>nl</B
>: A self-numbering script.</A
></DT
><DT
>12-26. <A
HREF="textproc.html#MANVIEW"
><B
CLASS="COMMAND"
>manview</B
>: Viewing formatted manpages</A
></DT
><DT
>12-27. <A
HREF="filearchiv.html#EX48"
>Using <B
CLASS="COMMAND"
>cpio</B
> to move a directory tree</A
></DT
><DT
>12-28. <A
HREF="filearchiv.html#DERPM"
>Unpacking an <I
CLASS="EMPHASIS"
>rpm</I
> archive</A
></DT
><DT
>12-29. <A
HREF="filearchiv.html#STRIPC"
>Stripping comments from C program files</A
></DT
><DT
>12-30. <A
HREF="filearchiv.html#WHAT"
><B
CLASS="COMMAND"
>Exploring <TT
CLASS="FILENAME"
>/usr/X11R6/bin</TT
></B
></A
></DT
><DT
>12-31. <A
HREF="filearchiv.html#WSTRINGS"
>An <SPAN
CLASS="QUOTE"
>"improved"</SPAN
> <I
CLASS="EMPHASIS"
>strings</I
>
	        command</A
></DT
><DT
>12-32. <A
HREF="filearchiv.html#FILECOMP"
>Using <B
CLASS="COMMAND"
>cmp</B
> to compare two files
	        within a script.</A
></DT
><DT
>12-33. <A
HREF="filearchiv.html#EX35"
><B
CLASS="COMMAND"
>basename</B
> and <B
CLASS="COMMAND"
>dirname</B
></A
></DT
><DT
>12-34. <A
HREF="filearchiv.html#FILEINTEGRITY"
>Checking file integrity</A
></DT
><DT
>12-35. <A
HREF="filearchiv.html#EX52"
>Uudecoding encoded files</A
></DT
><DT
>12-36. <A
HREF="communications.html#SPAMLOOKUP"
>Finding out where to report a spammer</A
></DT
><DT
>12-37. <A
HREF="communications.html#ISSPAMMER"
>Analyzing a spam domain</A
></DT
><DT
>12-38. <A
HREF="communications.html#QUOTEFETCH"
>Getting a stock quote</A
></DT
><DT
>12-39. <A
HREF="communications.html#FC4UPD"
>Updating FC4</A
></DT
><DT
>12-40. <A
HREF="communications.html#REMOTE"
>Using ssh</A
></DT
><DT
>12-41. <A
HREF="communications.html#SELFMAILER"
>A script that mails itself</A
></DT
><DT
>12-42. <A
HREF="mathc.html#MONTHLYPMT"
>Monthly Payment on a Mortgage</A
></DT
><DT
>12-43. <A
HREF="mathc.html#BASE"
>Base Conversion</A
></DT
><DT
>12-44. <A
HREF="mathc.html#ALTBC"
>Invoking <B
CLASS="COMMAND"
>bc</B
> using a <SPAN
CLASS="QUOTE"
>"here
	        document"</SPAN
></A
></DT
><DT
>12-45. <A
HREF="mathc.html#CANNON"
>Calculating PI</A
></DT
><DT
>12-46. <A
HREF="mathc.html#HEXCONVERT"
>Converting a decimal number to hexadecimal</A
></DT
><DT
>12-47. <A
HREF="mathc.html#FACTR"
>Factoring</A
></DT
><DT
>12-48. <A
HREF="mathc.html#HYPOT"
>Calculating the hypotenuse of a triangle</A
></DT
><DT
>12-49. <A
HREF="extmisc.html#EX53"
>Using <B
CLASS="COMMAND"
>seq</B
> to generate loop arguments</A
></DT
><DT
>12-50. <A
HREF="extmisc.html#LETTERCOUNT"
>Letter Count"</A
></DT
><DT
>12-51. <A
HREF="extmisc.html#EX33A"
>Using <B
CLASS="COMMAND"
>getopt</B
> to parse command-line
	        options</A
></DT
><DT
>12-52. <A
HREF="extmisc.html#SELFCOPY"
>A script that copies itself</A
></DT
><DT
>12-53. <A
HREF="extmisc.html#EXERCISINGDD"
>Exercising <B
CLASS="COMMAND"
>dd</B
></A
></DT
><DT
>12-54. <A
HREF="extmisc.html#DDKEYPRESS"
>Capturing Keystrokes</A
></DT
><DT
>12-55. <A
HREF="extmisc.html#BLOTOUT"
>Securely deleting a file</A
></DT
><DT
>12-56. <A
HREF="extmisc.html#TEMPFILENAME"
>Filename generator</A
></DT
><DT
>12-57. <A
HREF="extmisc.html#UNITCONVERSION"
>Converting meters to miles</A
></DT
><DT
>12-58. <A
HREF="extmisc.html#M4"
>Using m4</A
></DT
><DT
>13-1. <A
HREF="system.html#SETNEWPW"
>Setting a new password</A
></DT
><DT
>13-2. <A
HREF="system.html#ERASE"
>Setting an erase character</A
></DT
><DT
>13-3. <A
HREF="system.html#SECRETPW"
><B
CLASS="COMMAND"
>secret password</B
>:
	      Turning off terminal echoing</A
></DT
><DT
>13-4. <A
HREF="system.html#KEYPRESS"
>Keypress detection</A
></DT
><DT
>13-5. <A
HREF="system.html#ISCAN"
>Checking a remote server for <I
CLASS="EMPHASIS"
>identd</I
></A
></DT
><DT
>13-6. <A
HREF="system.html#KILLPROCESS"
><B
CLASS="COMMAND"
>pidof</B
> helps kill a process</A
></DT
><DT
>13-7. <A
HREF="system.html#ISOMOUNTREF"
>Checking a CD image</A
></DT
><DT
>13-8. <A
HREF="system.html#CREATEFS"
>Creating a filesystem in a file</A
></DT
><DT
>13-9. <A
HREF="system.html#ADDDRV"
>Adding a new hard drive</A
></DT
><DT
>13-10. <A
HREF="system.html#ROT13A"
>Using <B
CLASS="COMMAND"
>umask</B
> to hide an output file
	        from prying eyes</A
></DT
><DT
>13-11. <A
HREF="system.html#EX55"
><B
CLASS="COMMAND"
>killall</B
>, from <TT
CLASS="FILENAME"
>/etc/rc.d/init.d</TT
></A
></DT
><DT
>14-1. <A
HREF="commandsub.html#STUPSCR"
>Stupid script tricks</A
></DT
><DT
>14-2. <A
HREF="commandsub.html#CSUBLOOP"
>Generating a variable from a loop</A
></DT
><DT
>14-3. <A
HREF="commandsub.html#AGRAM2"
>Finding anagrams</A
></DT
><DT
>16-1. <A
HREF="io-redirection.html#REDIR1"
>Redirecting <TT
CLASS="FILENAME"
>stdin</TT
> using
	  <B
CLASS="COMMAND"
>exec</B
></A
></DT
><DT
>16-2. <A
HREF="io-redirection.html#REASSIGNSTDOUT"
>Redirecting <TT
CLASS="FILENAME"
>stdout</TT
> using
	  <B
CLASS="COMMAND"
>exec</B
></A
></DT
><DT
>16-3. <A
HREF="io-redirection.html#UPPERCONV"
>Redirecting both <TT
CLASS="FILENAME"
>stdin</TT
> and
	  <TT
CLASS="FILENAME"
>stdout</TT
> in the same script with
	  <B
CLASS="COMMAND"
>exec</B
></A
></DT
><DT
>16-4. <A
HREF="io-redirection.html#AVOIDSUBSHELL"
>Avoiding a subshell</A
></DT
><DT
>16-5. <A
HREF="redircb.html#REDIR2"
>Redirected <I
CLASS="EMPHASIS"
>while</I
> loop</A
></DT
><DT
>16-6. <A
HREF="redircb.html#REDIR2A"
>Alternate form of redirected <I
CLASS="EMPHASIS"
>while</I
> loop</A
></DT
><DT
>16-7. <A
HREF="redircb.html#REDIR3"
>Redirected <I
CLASS="EMPHASIS"
>until</I
> loop</A
></DT
><DT
>16-8. <A
HREF="redircb.html#REDIR4"
>Redirected <I
CLASS="EMPHASIS"
>for</I
> loop</A
></DT
><DT
>16-9. <A
HREF="redircb.html#REDIR4A"
>Redirected <I
CLASS="EMPHASIS"
>for</I
> loop (both
	  <TT
CLASS="FILENAME"
>stdin</TT
> and <TT
CLASS="FILENAME"
>stdout</TT
>
	  redirected)</A
></DT
><DT
>16-10. <A
HREF="redircb.html#REDIR5"
>Redirected <I
CLASS="EMPHASIS"
>if/then</I
> test</A
></DT
><DT
>16-11. <A
HREF="redircb.html#NAMESDATA"
>Data file <SPAN
CLASS="QUOTE"
>"names.data"</SPAN
> for above examples</A
></DT
><DT
>16-12. <A
HREF="redirapps.html#LOGEVENTS"
>Logging events</A
></DT
><DT
>17-1. <A
HREF="here-docs.html#EX70"
><B
CLASS="COMMAND"
>broadcast</B
>: Sends message to everyone logged in</A
></DT
><DT
>17-2. <A
HREF="here-docs.html#EX69"
><B
CLASS="COMMAND"
>dummyfile</B
>: Creates a 2-line dummy file</A
></DT
><DT
>17-3. <A
HREF="here-docs.html#EX71"
>Multi-line message using <B
CLASS="COMMAND"
>cat</B
></A
></DT
><DT
>17-4. <A
HREF="here-docs.html#EX71A"
>Multi-line message, with tabs suppressed</A
></DT
><DT
>17-5. <A
HREF="here-docs.html#EX71B"
>Here document with parameter substitution</A
></DT